1. Field of the Invention
The present invention relates to a conductive cylindrical support for a photoconductor for laser printers, copying machines, facsimile machines, and so forth.
2. Description of the Related Art
The conventional photoconductive support for xerography is constructed on a cylindrical conductive support having flanges. The cylindrical conductive support (about 0.1 cm thickness) has a photoconductive layer formed on its outer periphery. A synthetic resin or a metal flange is crimped or adhered to both open end portions of the cylindrical conductive support.
For example, the conductive supports as shown in FIGS. 14 and 15 have been widely applied. The material of the photoconductive supports is a metal such as aluminum. The dimensions of the support are such that the outer diameter is around 6.0 cm; the length is around 24.0 cm; the thickness is around 0.1 cm; and the weight is around 120 g. The conductive support made of the cylindrical metal is comparatively light in weight because it is hollowed. Thus, such a conductive body helps to reduce the load applied to the drive system. However, it is difficult to accurately match the rotating axis of the cylindrical support with the rotating axis of the flange by a mechanical working or the like. Consequently, the photoconductive layer formed on the outer periphery of the support vibrates in the driving and the rotating process thereby adversely affecting each xerographic process. For example, since the gap between the surface of the photoconductor and the developer physically varies while the cylindrical support rotates unevenly developed images take place. In addition, since the length of the optical path varies, unsharp latent images take place and/or the resolution is decreased. Moreover, since the distance between the cylindrical support and the corona wire varies, uneven discharge takes place.
A producing method of substrate for excellent photoconductors is disclosed in Japanese Patent Tokkaisho No-57-139746. This invention particularly relates to a burnishing method of the surface of cylindrical photoconductors with a diameter of around 12 cm. However, this invention does not disclose conductive supports with a small outer diameter for providing photoconductors. In addition, this invention does not disclose a drive transferring mechanism which is coaxially unified with a photoconductive support.
To construct laser printers and copying machines in small sizes, the outer diameter of the cylindrical supports should be small. However, in this case, the moment of inertia of the cylindrical support remarkably is decreased. Thus, the support unevenly rotates and thereby uneven images take place in the vertical scanning direction of the laser printers and so forth.
To solve such a problem, if the moment of inertia of the cylindrical support is increased, the outer diameter and the weight thereof inevitably are increased. Thus, the drive system is excessively loaded and thereby remarkably shortens the service lives of the motors and gears used therein. In particular, when plastic gears, which are easily worked, are used, the service life thereof is further shortened.